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I can understand your perspective since I've lived with Type 1 diabetes for most of my life. However, CGM is a technology which may have serious, life-threaten
by davidthewatson 4y ago
I can understand your perspective since I've lived with Type 1 diabetes for most of my life.
However, CGM is a technology which may have serious, life-threatening side effects when its data is inaccurate and used in concert with a hybrid closed loop insulin pump. In patients like me, the frequency of bad data is daily.
"Being able to know what your blood sugar is with no effort at all, and being alerted when it's high or low... is just life changing".
That may be true as long as we include death and serious injury as the "life changing" events that they are.
CGM is useful technology but "life changing" is assuming a level of execution that does not exist in the current generations of CGM technology that I've used, which include Dexcom G6 and Freestyle Libre 2.
It is well understood in the research community of MD-PhD's that interstitial fluid in adipose tissue is a reasonable proxy for plasma blood glucose with the correct algorithmic approach, but it is not perfect.
Particularly in patients who have low adipose tissue, the data emitted from these sensor devices is frequently wrong at fasting times such as exercise and sleep.
I've worn an insulin pump for more than twenty years and used Medtronic, Dexcom, and Abbott for their CGM data in recent years.
The sensors have been replaced under warranty dozens of times, due to inaccurate readings, the last of which I submitted today, when the pump alarmed at 1:30 AM last night reporting that my CGM BG was 50, when my plasma BG reading was 112, the former of which is hypoglycemic while the latter of which is slightly hyperglycemic. I've seen much larger variations than that.
We'll leave the fact that my quality of sleep has been destroyed by these devices for another discussion. This is frequently nightly.
The problem is this: at night or during exercise, when fasting states are both reasonable and customary since it's difficult to eat and sleep or eat and exercise concurrently, innacurate CGM data can induce the pump to either increase insulin delivery, decrease insulin delivery, or stop delivery entirely.
In turn, those 3 conditions can result in hypoglycemia or hyperglycemia, either of which can result in injury or death.
So while diabetes is a difficult disease, it must be noted that exogenous insulin is like any other prescription medication - there are side effects.
Further, technological solutions such as hybrid closed loop insulin pump systems, when used in concert with CGM, may have deadly side effects that are not clearly communicated, nor are they pursued with vigor in the billion dollar companies who promote these products.
Given what I've seen, I've merely warned my doctor and the FDA of the need for oversight and regulation in these markets.
I'm hopeful that the products do eventually get fixed, but having worked in medical devices, I'm not optimistic given the history of the FDA's involvement in insulin pump security breaches in the last decade.
- heisenzombie 4y agoI agree that they’re quite imperfect. However, as people with Type 1 we don’t have the option of perfect. The alternative to CGMs is finger- pricking. The alternative to pumps is long-acting insulin. A semi-closed loop pump will give you a basal rate that changes through the day, informed by the CGM. A long-acting insulin dose (eg, Lantus) will give you a basal rate that changes through the day, due to absorption rate, temperature, exercise, etc. Now, neither Basal rate will match your bodies needs minute-by-minute. But even with the CGM & looped pump regularly getting it wrong (which it does), it’s still I think getting it much less wrong than inject-and-pray long-acting insulin treatment. As for risks, I had to do two days of training to get my pump and another online course to turn in the hybrid-closed-loop. That’s more than when I was given a glucometer and insulin pen when I was diagnosed, and it’s pretty easy to kill yourself with those.
- davidthewatson 4y agoI don't think you're understanding the problem. Two days of training is incredibly short given the complexity. Killing yourself at your own hand is well-understood culturally, clinically, and legally. The mechanisms of insulin-induced trauma have been well understood since insulin shock therapy: https://en.wikipedia.org/wiki/Insulin_shock_therapy https://en.wikipedia.org/wiki/Insulin_shock_therapy and Klaus von Bulow: https://en.wikipedia.org/wiki/Sunny_von_B%C3%BClow https://en.wikipedia.org/wiki/Sunny_von_B%C3%BClow Being killed by a machine, on the other hand, directly or indirectly may be understood culturally from the long list of science fiction films featuring killer robots, but less so clinically and legally, because we don't have agreement or consensus on accidental death and the role of technology in rising risks in a complex systems environment. We need to take the implications of the design of medical device autonomy seriously as we approach these problems with those solutions, since they often fail a definition of complete autonomy, but may in fact be considered close enough to pass the same standard of risk and care as we'd give to autonomous robots in industrial settings or self-driving cars. Just because the administration of drugs doesn't seem particularly robotic, when that administration is beyond a certain percentage of machine control, I'd argue that it is behaving autonomously even though the control mechanisms fall short of machine learning. It's as if we took Therac 25 and strapped it to a patient's belt with the oncology planning encoded in the radiation device. It may seem as if the complexity is less, but we don't have consensus on that either: https://www.scielo.br/j/rbepid/a/Mn7DTtCYQLL5gkJgBb8XP3q/?lang=en&format=html https://www.scielo.br/j/rbepid/a/Mn7DTtCYQLL5gkJgBb8XP3q/?la... https://en.wikipedia.org/wiki/Therac-25 https://en.wikipedia.org/wiki/Therac-25